Man held over Westminster security alert

A man was was being questioned by police today after a security alert was sparked when white powder was thrown in the Palace of Westminster.

The central lobby at Westminster was sealed off and officers wearing protective overalls, gas masks and gloves were seen entering the area.

The man spread the unidentified substance at around 6pm last night and was detained at the scene.

But about half an hour later the all-clear was given and the Palace was fully reopened.

Unconfirmed reports suggested the powder was being tested in case it was anthrax but Labour MP Keith Vaz (Leicester East) who was in the central lobby at the time of the incident, said he believed the substance was wheat-flour.

He said he believed there should have been a public address announcement.

"This shows once again that they should look at the way they do Commons security," he said.

The alert did not affect either sittings of the House. MPs and peers continued their debates although no one was allowed to leave the Palace and the entrances and exits were sealed.

Members of the public, officials and police who were present during the incident were kept in the central lobby while the powder was investigated.

The entrances and exits were later reopened as officials confirmed that the incident was officially over.

All visitors to the Palace are subject to stringent security checks after a series of breaches in recent years, including one in May 2004 when a Fathers 4 Justice campaigner threw purple powder at the Prime Minister at question time.

Later in the year five pro-hunting protesters stormed the floor of the Commons, causing the sitting to be suspended.

Security has since been stepped up with a high-tech security screen placed between the public gallery and the Commons chamber.

And no member of the public is allowed to go beyond the central lobby unless accompanied by a Commons pass holder.